Fig. 3

Example images of the capillary experiments a the position of the crystals before the experiments, b NaCl solution at 90% (start RH) and c completed crystallization of NaCl at 20% (target RH). Note the location of the crystals deeper into the capillary compared to the image on the left. Visualized at a magnification of 160 with digital microscopy (HIROX) in a microclimate chamber (GenRH/Mcell)